Sofa



FIG. 1 is a front and side perspective view of the sofa of my design;

FIG. 2 is a front view of the sofa;

FIG. 3 is a back view of the sofa;

FIG. 4 is a top view of the sofa; and,

FIG. 5 is a left side view of the sofa (the right side view is a mirror image of this view and is not shown).

The bottom of the sofa forms no part of the claimed design. 

The ornamental design for a sofa, as shown and described. 